Serial.print__ - jimaobian/DFRobotWikiCn GitHub Wiki

往串口发数据,无换行 描述 以人类可读的ASCII码形式向串口发送数据,该函数有多种格式。整数的每一数位将以ASCII码形式发送。浮点数同样以ASCII码形式发送,默认保留小数点后两位。字节型数据将以单个字符形式发送。字符和字符串会以其相应的形式发送。例如:


    Serial.print(78) 发送 "78"
    Serial.print(1.23456) 发送 "1.23"
    Serial.print('N') 发送 "N"
    Serial.print("Hello world.") 发送 "Hello world."

可选的第二个参数用于指定数据的格式。允许的值为:BIN (binary二进制), OCT (octal八进制), DEC (decimal十进制), HEX (hexadecimal十六进制)。对于浮点数,该参数指定小数点的位数。例如:

    Serial.print(78, BIN) gives "1001110"
    Serial.print(78, OCT) gives "116"
    Serial.print(78, DEC) gives "78"
    Serial.print(78, HEX) gives "4E"
    Serial.println(1.23456, 0) gives "1"
    Serial.println(1.23456, 2) gives "1.23"
    Serial.println(1.23456, 4) gives "1.2346"

你可以用F()把待发送的字符串包装到flash存储器。例如:

    Serial.print(F(“Hello World”))

要发送单个字节数据,请使用Serial.write()。

语法:

Serial.print(val)
Serial.print(val, format)

参数:

  • val: 要发送的数据(任何数据类型)
  • format: 指定数字的基数(用于整型数)或者小数的位数(用于浮点数)。

返回值:<>

  • size_t (long): print()返回发送的字节数(可丢弃该返回值)。

示例:

/*
Uses a FOR loop for data and prints a number in various formats.
*/
int x = 0;    // variable

void setup() {
  Serial.begin(9600);      // open the serial port at 9600 bps:
}

void loop() {
  // print labels
  Serial.print("NO FORMAT");       // prints a label
  Serial.print("\t");              // prints a tab

  Serial.print("DEC");
  Serial.print("\t");

  Serial.print("HEX");
  Serial.print("\t");

  Serial.print("OCT");
  Serial.print("\t");

  Serial.print("BIN");
  Serial.print("\t");

  for(x=0; x< 64; x++){    // only part of the ASCII chart, change to suit

    // print it out in many formats:
    Serial.print(x);       // print as an ASCII-encoded decimal - same as "DEC"
    Serial.print("\t");    // prints a tab

    Serial.print(x, DEC);  // print as an ASCII-encoded decimal
    Serial.print("\t");    // prints a tab

    Serial.print(x, HEX);  // print as an ASCII-encoded hexadecimal
    Serial.print("\t");    // prints a tab

    Serial.print(x, OCT);  // print as an ASCII-encoded octal
    Serial.print("\t");    // prints a tab

    Serial.println(x, BIN);  // print as an ASCII-encoded binary
    //                             then adds the carriage return with "println"
    delay(200);            // delay 200 milliseconds
  }
  Serial.println("");      // prints another carriage return
}

编程技巧: 在版本1.0时,串口传输是异步的,Serial.print()会在数据发送完成前返回。